// jiech.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

int main(int argc, char* argv[])
{
	int i=1,n,sum=1;
	scanf("%d",&n);
	while(i<=n)
	{
		sum=sum*i;i=i+1;
	}
	printf("%d",sum);

	return 0;
}

